1. Field of the Invention
The present invention relates generally to a deodorizing device, and more particularly, to a deodorizing device having the function of removing odor components from within a refrigerator.
2. Description of the Related Art
Within the refrigerator, odors are issued from various food articles such as fish, meat, vegetables, etc., and odors are accumulated because of the circulation in the sealed space, and further adhere to food articles, resulting in the deterioration of the quality of food articles.
For solution of these problems, there has been proposed a deodorizing device for the refrigerator such as described in Japanese Laid-open Patent Publication No. 2-194816.
A conventional deodorizing device for the refrigerator will be described below.
FIG. 1 is a longitudinal sectional view of an upper portion of a refrigerator showing a state wherein the conventional deodorizing device is arranged in the refrigerator. FIG. 2 is an enlarged cross-sectional view of the deodorizing device and FIG. 3 is an enlarged partially broken side view thereof.
First in FIG. 1, there are shown a refrigerator main body 1, a freezing chamber 2 and a cold storage chamber 3 formed therein with respective doors 4 and 5. A cooling coil 6 is arranged in a cooling coil chamber 7 positioned at the back side of said freezing camber 2, and a fan 8 is arranged above the cooling coil 6. When the fan 8 is driven, the freezing chamber 2 is cooled by the air circulation, wherein part of the air cooled by the cooling coil 6 is supplied into the freezing chamber 2 from a supply port 9, and the air within the freezing chamber 2 is returned to the cooling coil chamber 7 through a return duct 10.
Meanwhile, the cold storage chamber 3 is cooled by the air circulation, wherein part of the air cooled by the cooling coil 6 is supplied into the cold storage chamber 3 through a supply duct 11, and the air therein is returned to the cooling coil chamber 7 through a return duct 12. In this case, the cooling coil chamber 7, the freezing chamber 2 and the return duct 10 constitute the circulation path for circulating the air within the freezing chamber 2, while the cooling coil chamber 7, the supply duct 11, the cold storage chamber 3 and the return duct 12 constitute the circulation path for circulating the air within the cold storage chamber 3.
Reference numeral 13 represents a defrosting heater provided under the cooling coil 6 in the lower portion of the cooling coil chamber 7, constituted by a glass tube heater wherein a heating wire 13b is provided in a glass tube 13a as shown in FIG. 3. The defrosting heater 13 is on-off controlled so as to be energized only in defrosting the cooling coil 6, and to otherwise to be cut off. Reference numeral 14 represents a water droplet prevention member provided so as to cover the defrosting heater 13 from above, which is made of a metallic plate, for example heat-resistant and water-resistant aluminum or the like, and formed in the shape of a downward opened shallow-bottomed container, as shown also in FIG. 2, for preventing the defrosted water from falling on the defrosting heater 13 during the defrosting cycle.
Reference numeral 15 represents a deodorizing member, which is of a two-layered structure comprised of a adsorption agent layer 15a made of adsorbing agent such as silica (silicon dioxide) or the like and a catalyst layer 15b made of platinum nickel or the like, provided on the adsorption agent layer 15a. Here, the adsorption member 15 is formed by forming the plate-shaped adsorption agent layer 15a through sintering the adsorption agent, applying the catalyst on its surface through immersing the adsorption agent layer 15a into the catalyst solution, and thereafter subjecting the same to heat treatment for forming the catalyst layer 15b on the surface of the adsorption agent layer 15a.
Furthermore, the adsorption agent layer 15a and catalyst layer 15b are respectively of porous structures so as allow air to pass therethrough. The deodorizing member 15 is supported and fixed on the inner face of the water droplet prevention member 14 by support fittings 17 through an insulation member 16 made of glass fiber or the like, thus positioned above and near said defrosting heater 13.
Reference numeral 18 indicates a cover member, for example a metallic net formed so as to have a large number of through holes, made of a high heat conductivity material and provided so as to cover the surface of the deodorizing member 15.
With respect to the deodorizing device for the refrigerator constituted as described above, the operation will be described below.
In the above structure, during the cooling cycle, the air within the refrigerator is circulated by the fan 8 through the cooling coil chamber 7, the freezing chamber 2 and the return duct 10 and through the cooling coil chamber 7 the supply duct 11, the cold storage chamber 3 and the return duct 12. In this case, the air passing through the cooling coil chamber 7 contacts the deodorizing member 15 through the through holes of the metallic net so that the odor components contained in the air is adsorbed by the adsorption agent layer 15a of the deodorizing member 15.
On the other hand, when the defrosting cycle is started, the operation of the cooling coil 6 and the fan 8 is stopped, while the defrosting heater 13 is energized to be heated. By the heating of the defrosting heater 13, the cooling coil 6 is heated so as to be defrosted, and simultaneously the deodorizing member 15 is heated. In this case, since the surface of the deodorizing member 15 is covered by the metallic net 18, by the heat conduction of this metallic net 18 the deodorizing member 15 is heated as uniformly as possible. In the heated deodorizing member 15, the odor components adsorbed by the adsorption agent layer 15a are decomposed and released, and at the same time, the odor components are decomposed and removed through oxidization in the catalyst layer 15b.
Thus, in the deodorizing member 15, the adsorption function, that is, the deodorizing function is regenerated by heating. In this case, the water droplet prevention member 14 contains the heat from the defrosting heater 13 therebelow and plays the role of efficiently heating the deodorizing member 15 and prevents the defrosted water from the cooling coil 6 from falling on the deodorizing member 15 and the defrosting heater 13.
The insulation member 16 holds the heat discharge of the deodorizing member 15 from the water droplet prevention member 14, and also prevents heat shock of the deodorizing member 15 due to rapid cooling of the water droplet prevention member 14 arising from the defrosted water dropped thereon.
Furthermore, the metallic net 18 prevents the deodorizing member 15 from being scattered and falling when the deodorizing member is broken.
When the defrosting cycle is completed and the cooling cycle is resumed, resulting in the decrease of the temperature of the deodorizing member 15, as described above, the odor components contained in the air within the refrigerator are adsorbed by the deodorizing member 15 to thereby be removed.
In the above constitution, however, besides the water droplet prevention member 14, the deodorizing member 15, the insulation member 16, the support fittings 17 and the metallic net 18 intervene between the defrosting heater 13 and the cooling coil 6, resulting in a complicated structure.
Furthermore, as a result, it is necessary to increase the thickness and size of the water droplet prevention member 14 for holding the deodorizing member 15, and also necessary to reduce the distance between the defrosting heater 13 and the water droplet prevention member 14 for raising the temperature of the deodorizing member 15. From the above, the linear radiation heat from the defrosting heater 13 and the rise of the convection heat to the cooling coil 6 are hampered, resulting in such a disadvantage that the defrosting time is increased and the defrosting performance of the refrigerator is lowered.
Furthermore, due to the fact that one face of the deodorizing member is in contact with the insulation member 16, the metallic net 18 covers the surface of the deodorizing member 15 and the water droplet prevention member 14 is required to be increased in size, there is such a disadvantage that the circulated air flow hitting the deodorizing member 15 is poor, resulting in a lowered deodorizing effect.